UTRECHT MICROPALEONTOLOGICAL BUllETINS

placed against the background of the British chronostratigraphic scale
(fig. 19). This procedure will give an idea of the approximate chronostratigraphic
position of the conodont-biozones of N.W. bland. Subsequently, our
conodont-zonation will be compared with Lindstrom's (1971) conodontzonation
of the Lower Ordovician of Europe; with Sergeeva's (1964, 1966)
conodont-zonation of the Ordovician of the Leningrad region; and with the
conodont faunas of the Ordovician of Estonia, reported by Viira, Kivimagi
and Loog (1970).
m.2., BIOSTRATIGRAPHIC AND CHRONOSTRATIGRAPHIC CORRELATIONS OF THE OLAN-
DIAN CONODONT-
AND TRILOBITE-ZONATIONS
As the Paradoxides fauna is generally accepted to be indicative for the
Middle Cambrian, the presence of Paradoxides paradoxissimus (WAHLEN-
BERG) (= Paradoxides tessini BROGNIART, 1822 = Entomostraeites
paradoxissimus WAHLENBERG, 1821) proves the Middle Cambrian age of
the "Tessini sandstone".
The chronostratigraphic position of the Zone of Agnostus pisiformis,
reported by Westergard (1922) from member D ii -d2 and the lower portion of
member Da-d3 between Aleklinta and Djupvik (figs. 11 and 13), is not quite
certain. Westergard considered this zone to be the lowermost zone of the
Swedish "Olenid shale" (= Upper Cambrian). According to Stubblefield
(1956, p.33) the Zone of Agnostus pisiformis has not been found in the
type-area of the Upper Cambrian in Britain.
Between Aleklinta and Djupvik the Cordylodus angulatus/C.prion Zone
has been found in the conglomerate of member Da-d 3, which would correspond
with the Dietyonema flabelliforme typiea Zone according to Westergard
(1947, see fig. 13); which in turn, is approximately correlative with
both Hede's (1951) Zone of Dietyonema flabelliforme and the British Zone
of Dietyonema flabelliforme as given in the International Stratigraphical
Lexicon, 1956, vol. I, fasc. 2a and fasc. 3a IV (see also figs. 11 and 19).
The Cordylodus rotundatus Zone is more difficult to place in the macrofossil-zonations.
It was found at Kopingsklint below the Subzone of Diet yonema
flabelliforme norvegieum and Bryograptus kjerulfi (compare fig. 12
and chart II) whereas the Cordylodus rotundatus Zone is thought to be
younger than the Zone of Cordylodus angulatus/C.prion. In Hede's (1951)
biozonation (see figs. 11 and 19) the Cordylodus rotundatus Zone thus
might be approximately equivalent to part of, or the entire Zone of Adelograptus
hunnebergensis and/or part of his Zone of Dietyonema flabelliforme